PCA66-TPB Contemporary Controls 90C66 AT Twisted-Pair Bus ARCNET Network Interface Module for ISA Bus Computers

The Contemporary Controls PCA66 Series ARCNET Network Interface Modules (NIMs) for ISA Bus Computers links ISA compatible computers with the ARCNET local area network.

ARCNET is classified as a token-bus LAN operating at 2.5 Mbps while supporting 255 nodes. Interfacing ARCNET to a host computer usually requires a NIM which plugs into the host computer's bus.

The PCA66 incorporates the 16-bit COM90C66 ARCNET controller chip with enhanced features over the earlier generation ARCNET chips. Features include command chaining and sequential I/O mapping of the internal RAM buffer. There is usually no requirement for wait-state arbitration. The PCA66 is backward compatible with earlier generation 90C26 and 90C65 8-bit ARCNET controllers and will operate as a replacement. However, to utilize the expanded features of the COM90C66, an enhanced software driver is required.

Each PCA66 module has two LEDs on the board. The green LED indicates that the module is transmitting data on the network and the yellow LED indicates bus access to the module. The PCA66 also has an external DIP switch so that node addresses can be easily reassigned without removing the module. There are five versions of the PCA66 ARCNET NIM. The PCA66-CXS supports coaxial star configurations requiring external active or passive hubs. The PCA66-CXB supports coaxial bus configuration usually requiring no hubs. Other versions include the PCA66-FOG which supports fiber optic cable with either ST or SMA connectors. The PCA66-TPB supports twisted-pair bus cabling using RJ-11 or screw terminal connectors.